PROJECT SUMMARY The overall objective of this study is to investigate longitudinal associations between cognition, health literacy (HL), and self-care in patients with chronic obstructive pulmonary disease (COPD), and determine whether social support from informal caregivers mitigates these associations. Cognitive function, a major component of HL, declines progressively in many COPD patients. HL might change over time as well, progressively altering COPD patients' ability to understand and use health information. However, longitudinal data on HL are not available. It is also unknown whether acute COPD exacerbations temporarily worsen cognition and HL, as might be expected owing to hypoxemia. Informal caregivers frequently help COPD patients manage their health at home, but little is known about the extent to which social support compensates for the HL and cognitive limitations of these patients, and whether caregivers' own problems of HL limit their ability to help others manage their chronic disease. Elucidating these issues could provide important data for developing interventions aimed at both patients and caregivers to overcome HL and cognition barriers to successful COPD management, and perhaps to other chronic diseases as well. Accordingly, the Specific Aims of this study are to (1) Examine longitudinally the trajectory of HL among patients with COPD, both as the disease progresses over time and following acute exacerbations; (2) Assess the association between HL, and it subcomponents, and specific self-management behaviors in patients with COPD, such as medication adherence and inhaler technique; (3) Evaluate the mitigating role of support from informal caregivers and caregivers' HL on the relationship between patients' HL and COPD self-management. We will address these aims by conducting a study of 400 English and Spanish-speaking adults with COPD from two socioeconomically and racially diverse inner-city primary care practices in New York City, NY and Chicago, IL. Patients will be followed for 2 years to collect data on HL, cognitive function, COPD symptoms and self-management behaviors. These data will also be assessed at the time of a hospital discharge for COPD exacerbation and one week later. Additionally, 100 informal caregivers of a subset of patients with COPD will be interviewed to determine their HL. This study is innovative in its longitudinal examination of the effects of HL and cognitive function and the potential mitigating role of caregiver support and caregiver HL. It will expand our understanding of the mechanisms through which HL and cognition influence COPD self-management, offering us an opportunity to design interventions to improve outcomes in a highly vulnerable population.